This is a detailed comparison between the Garmin 645 vs 745. They are both excellent Garmin watches, but the FR745 definitely brings more sports tracking features to the table.
The Garmin Forerunner 645 is a mid-range GPS watch built primarily for runners. It has onboard music storage, a solid selection of sports features, advanced running dynamics, and support for Garmin running power.
The Forerunner 745 is a significant upgrade on the Forerunner 645. Support for open water swimming, triathlon tracking, and cycling power meters are massive upgrades, but the list doesn’t end there. The FR745 also has a pulse oximeter (to measure blood oxygen levels), personalized workout recommendations, and better battery life.
In essence, the Forerunner 745 can do everything that the Forerunner 645 can, plus a whole lot more. It is a better smartwatch, a better fitness tracker, and a better sports watch. The only reason to truly consider the FR645 is price, given that the Forerunner 645 is significantly cheaper than the Forerunner 745.
Table of Contents
Key Similarities - Forerunner 645 vs 745
Forerunner 645
Forerunner 745
Key Differences - Forerunner 645 vs Forerunner 745
FR645
FR745
Main Reasons To Choose The Forerunner 645
1. It's cheaper, and you might be able to find it on special
There is only one reason to choose the Forerunner 645. That reason is price.
To be more specific, it only makes sense to go for the FR645 if you can find it on special, and you have no interest in triathlon tracking. However, if the FR645 isn’t being discounted, you can unlock a huge number of benefits by upgrading to the FR745. It can literally do everything that the FR645 can do, plus a whole lot more.
On this point, it’s worth noting that you should be able to find the non-music version of the Forerunner 645 for at least $100 cheaper than the FR745. If you’re not planning to use the music features and you don’t do triathlons, you can make a strong case for the value premise of the non-music FR645.
Main Reasons To Choose The Forerunner 745
1. Open Water Swimming + Triathlon Tracking
Open water swimming and triathlon tracking tend to go hand-in-hand. If you opt for the Forerunner 745, you can unlock both of these features. To switch between each triathlon discipline, you simply need to push one button on the FR745.
2. Garmin PacePro + Garmin ClimbPro
Garmin PacePro: PacePro offers pace guidance for to help you stay on track during training. When PacePro is applied to a course loaded to your watch, it analyzes elevation changes along the course to calculate a pace strategy. The strategy calculates when to increase or decrease your pace along the course for the best overall pace.
Garmin ClimbPro: ClimbPro detects the climb sections of a cycling course. When ClimbPro is activated, you will be able to see:
- The number of the climb including total climbs for the course
- The distance remaining in the climb (Dist. to Go)
- The ascent remaining for the climb (Asc. Remain.)
- A chart showing the profile of the climb
- The total climb distance
- The remaining distance to each climb (Dist. to)
- Average gradient for each climb (Grade)
- Length of each climb
3. Pulse Ox Sensor (Blood Oxygen Measurements)
This wrist-based sensor in the FR745 monitors blood oxygen saturation levels to provide a clearer picture of how you’re sleeping or how you’re adjusting to altitude.
4. Body Battery Score
Garmin’s body battery score combines your training data, sleeping data and heart rate data into one overarching metric called Body Battery Score.
Most new Garmin’s (any watch with Garmin’s V3 elevate heart rate monitor) have the Body Batter Feature built-in. Unfortunately the FR645 was released a few months before the V3 heart rate monitor became the default setup for new Garmin activity trackers.
5. Better Cycling Features + Cycling Power Meter Compatibility
The Garmin Forerunner 745 is a better sports watch for cyclists specifically. You can access additional cycling modes, functional threshold power, and cycling power meter compatibility. The bullet points below highlight the difference between the FR645 and the FR745 in terms of cycling features.
FR645 Cycling Features
- Cycling Alerts
- Cycling Courses
- Outdoor Cycling
- Indoor Cycling
- Race an activity
- Compatible with Varia Vision
- Compatible with Varia Radar
- Compatible with Varia Lights
- Speed and Cadence Sensor Support
FR745 Cycling Features
- Cycling Alerts
- Cycling Courses
- Outdoor Cycling
- Indoor Cycling
- Race an activity
- Compatible with Varia Vision
- Compatible with Varia Radar
- Compatible with Varia Lights
- Speed and Cadence Sensor Support
- Mountain Trail Biking
- Bike Lap And Lap Maximum Power
- Functional Threshold Power (FTP)
- Cycling Power Meter Compatible
- Advanced Vector Support
Sports Tracking Comparison
FR645 Fitness Tracking Features
- Strength Training
- Cardio Training
- Elliptical Training
- Stair Stepping
- Floor Climbing
- Indoor Rowing
- Yoga
- Running
- Treadmill Running
- Indoor Track Running
- Trail Running
- Skiing
- Snowboarding
- XC Skiing
- Stand Up Paddleboarding
- Rowing
- Cycling
- Indoor Cycling
- Pool Swimming
- Walking
FR745 Fitness Tracking Features
- Strength Training
- Cardio Training
- Elliptical Training
- Stair Stepping
- Floor Climbing
- Indoor Rowing
- Yoga
- Running
- Treadmill Running
- Indoor Track Running
- Trail Running
- Skiing
- Snowboarding
- XC Skiing
- Stand Up Paddleboarding
- Rowing
- Cycling
- Indoor Cycling
- Pool Swimming
- Walking
- Pilates
- Outdoor Track Running
- Virtual Running
- Kayaking
- Mountain Biking
- Open Water Swimming
- Swimrun
- Triathlon Tracking
Final Thoughts
When you compare all the features of these two Garmin Smartwatches, it’s pretty clear that the Forerunner 745 is the winner of this product battle. Nevertheless, if you’re still on the fence at this point, these final buying tips may help:
Go for the Forerunner 645 if:
- You have no interest in triathlon tracking
- You can find the FR645 on special
- Running is your primary sport
Go for the Forerunner 745 if:
- You want the better smartwatch overall
- You want Garmin’s latest technology like the pulse oximeter and body battery score
- You’re passionate about cycling
- You’re a triathlete